Path computation systems and methods for heterogeneous multi-domain networks

Abstract

The present disclosure provides path computation systems and methods operating over heterogeneous multi-domain networks. Specifically, path computation systems and methods utilize PCE mechanisms with additional functionality enabling heterogeneous domain characteristics. In an exemplary embodiment, a network includes a plurality of domains with each domain having a PCE implemented either as a separate server-based application or resident application in a network node. Different methods may be utilized for determining what PCE to access for information. Instead of a list of nodes and links given in a common format, each PCE can compute a path within its domain using a node and link address/identification format of its own, without having to ensure that it can be interpreted by nodes in other domains. This path segment can be further distinguished by a path identifier that verifies that it is created for a particular domain, and avoiding misinterpretation.

What is claimed is: 
     
       1. A path computation method across a multi-domain network, comprising:
 requesting a path setup from a node A in a domain A to a node Z in a domain Z; 
 receiving an Explicit Route Object comprising a path from the node A to the node Z, wherein the Explicit Route Object comprises an unparsed domain-specific path segment for domain Z or any intermediate domains between the domain A and the domain Z, and wherein the unparsed domain-specific path segment is not understood by the domain A; and 
 using the Explicit Route Object to set up a path from the node A to the node Z. 
 
     
     
       2. The path computation method of  claim 1 , wherein the unparsed domain-specific path segment is treated as a single, non-parsed object in the domain A. 
     
     
       3. The path computation method of  claim 1 , wherein the unparsed domain-specific path segment is utilized because the domain A uses a different addressing scheme and is not configured to parse the unparsed domain-specific path. 
     
     
       4. The path computation method of  claim 1 , wherein the requesting and receiving steps are performed by a Path Computation Element (PCE) in the domain A. 
     
     
       5. The path computation method of  claim 4 , wherein the unparsed domain-specific path segment is determined by a Path Computation Element (PCE) in the domain Z or any intermediate domains. 
     
     
       6. The path computation method of  claim 5 , wherein a PCE in the domain Z or any intermediate domains is configured to parse the unparsed domain-specific path segment during path setup. 
     
     
       7. The path computation method of  claim 5 , further comprising:
 with each PCE in each domain, temporarily reserving resources on a computed path segment in the Explicit Route Object; 
 using the reserved resources in path setup; and 
 if no setup message received for a predetermined time, releasing the temporarily reserved resources. 
 
     
     
       8. A multi-domain network, comprising:
 two or more domains; 
 a plurality of nodes in each of the two or more domains; 
 a first addressing scheme for the plurality of nodes in a first domain of the two or more domains; 
 a second addressing scheme for the plurality of nodes in a second domain of the two or more domains; 
 wherein a first node in the first domain is configured to receive an Explicit Route Object comprising a path from the first node to a second node in the second domain, wherein the Explicit Route Object comprises an unparsed domain-specific path segment for the second domain. 
 
     
     
       9. The multi-domain network of  claim 8 , wherein the unparsed domain-specific path segment is treated as a single, non-parsed object in the first domain. 
     
     
       10. The multi-domain network of  claim 8 , further comprising:
 a first Path Computation Element (PCE) in the first domain; and 
 a second PCE in the second domain. 
 
     
     
       11. The multi-domain network of  claim 10 , wherein the unparsed domain-specific path segment is determined by the second PCE. 
     
     
       12. The multi-domain network of  claim 11 , wherein the second PCE or node in the second domain is configured to parse the unparsed domain-specific path segment during path setup. 
     
     
       13. The multi-domain network of  claim 11 , wherein the second PCE is configured to:
 temporarily reserve resources on a computed path segment in the second domain in the Explicit Route Object; 
 use the reserved resources in path setup; and 
 if no setup message received for a predetermined time, release the temporarily reserved resources. 
 
     
     
       14. A Path Computation Element (PCE), comprising:
 an interface communicatively coupling the PCE to a plurality of nodes forming a first domain; 
 algorithms for path computation and setup; 
 a processor communicatively coupled to the interface and configured to execute the algorithms for path computation and setup; and 
 an algorithm to set up a path over heterogeneous domains outside the first domain; 
 wherein the algorithm to set up a path over heterogeneous domains outside the first domain comprises:
 requesting a path setup from a first node in the first domain to a second node in an external domain; 
 receiving an Explicit Route Object comprising a path from the first node to the second node, wherein the Explicit Route Object comprises an unparsed domain-specific path segment for the external domain or any intermediate domains between the first domain and the external domain, and wherein the unparsed domain-specific path segment is not understood by the PCE; and 
 using the Explicit Route Object to set up a path from the first node to the second node. 
 
 
     
     
       15. The PCE of  claim 14 , wherein the unparsed domain-specific path segment is treated as a single, non-parsed object in the first domain by the PCE. 
     
     
       16. The PCE of  claim 14 , wherein the unparsed domain-specific path segment is determined by a second PCE in the external domain or any intermediate domains. 
     
     
       17. The PCE of  claim 16 , wherein the second PCE or node in the second domain is configured to parse the unparsed domain-specific path segment during path setup. 
     
     
       18. The PCE of  claim 16 , wherein the second PCE is configured to:
 temporarily reserve resources on a computed path segment in the Explicit Route Object; 
 use the reserved resources in path setup; and 
 if no setup message received for a predetermined time, release the temporarily reserved resources.